Valve lifter mechanism



1934- T. M. MUELLER VALVE L IFTER MECHANISM INVENTOR.

nAA//////// Filed Jan. 50. 1935 miam $307 A ORNEY.

Patented Oct. 23, 1934 UNITED" STATES; psi-Ea OFFICE VALVE ur'mamommies:

- Theodore M. Mueller, Pontiac, Mich.

Applicationlanunry 30, 1933, Serial No. 654,151

4 Claims. (01. 123 90) My invention'relates to improvements in a valvelifter mechanism in which hydraulic pressure is utilized for taking uptappet clearance to provide decreased noise of operation and the objectsof my improvements are, first, to provide a valve lifter mechanismhaving a fluid valve mechanism located adjacent the lifted valvemechanism to decrease inertia forces exerted thereon; to provide a valvelitter mechanism utilizing hydraulic pressure with means for efiectivelysealing the valve lifter mechanism against leakage of the hydraulicmedium; third, to provide a valve litter mechanism having a fluid valveactuated by a resilient member that will exert no thrust against theengine valve and its resilient actuating means; fourth, to provide avalve litter mechanism having a hydraulically actuated piston or capmember between the valve lifter mechanism and the engine valvemechanism; fifth, to provide a valve lii'ter mechanism having a flat ordisc valve for controlling the flow of a hydraulic medium there.- with;sixth, to provide a valve litter mechanism having a hydraulicallyoperated clearance take up, means connected with a source of hydraulicpressure only when the valve to be lifted is at or adjacent its closedposition; seventh, to provide a valve litter mechanism having ahydraulically operated tappet clearance take up means from whichanamount of hydraulic medium is discharged, during the pressure or valvelifting stroke only, into the atmosphere outside of the valve liftermechanism; and eighth, to provide a valve lifter mechanism containing avolume of hydraulic medium trapped or isolated from its source ofsupply.

I attain these objects by mechanism illustrated in the accompanyingdrawing, in which- Figure 1 is a vertical section 01 the valve liftermechanism, together with an engine valve and its operating mechanism, ina closed position; Fig. 2,

' a vertical section of the valve litter mechanism,

together with the engine valve and its operating mechanism, in an openposition; Fig. 3, a side elevation of the valve liiter mechanism asdisclosed in Fig. 1 together with its valve liiter bracket; Fig. 4, avertical section of my valve hit-- er mechanism adapted for use in anengine equipped with an overhead valve mechanism; .Fig. 5. a. sideelevation of the member for limiting the movement of the hydraulicvalve; and Fig. 6, an end elevation of the member disclosed in Fig. 5. I

Similar numerals refer to similar parts throughout the several views.

Theliiter plunger 1 is slldably mounted in the litter bracket 2 which issuitably mounted in the cylinder block 3 of anengine assembly, thecylinder block 3 being disclosed in partial section with the valve 4having its stem 5 slidably mounted in the valve guide 6 which is pressedinto the cylin'der block 3. The cylinder head 7 is suitably 'attachedto'the cylinder block 3 and thereby provides the combustion chamber 8whichconnects with the valve passage 9 which is open and closed,relative to communication with the combustion chamber 8, by the valve 4.

The valve guide 6 may be provided with a portion extending into aconventional valve chamber or boxwhich surrounds and contains the valvelifter bracket-2 and the valve lifter mechanism. The valve guide 6 maybeprovided with the shoulder 11 which may position the valve guide 6 inthe cylinder 3 together with the retainer 10 there against, the retainer10 further retaining and locating the upper end of the valve spring 13concentrically with the valve guide 6.

The valve spring 12 is further secured in its operative position by theretainer member 13 which is retained by the members 14 which areconstructed in halves to permit assembly in the shouldered portion 15 ofthe valve stem 5, the members 14 thus being secured to the valve stem 5and absorbing the thrust of the valve spring 12 against the retainermember 13.

The above description of the conventional parts of an engine will aid inmore clearly disclosing the essential features of,my valve liftermechanism which is associated and operatively connected therewith. y

it is well known that the tappet clearance, necessarily incorporated invalve actuating mechanisms to accommodate the tendency of the enginevalve and associated parts'to vary in their dimensions due to beingsubjected to varying temperatures, is the cause of objectionable noisein the operation of the valve mechanism of internal combustion enginesas used in automotive ve- -'hicles and similar mechanisms.

Toeliminate objectionable noise and to assure 'quiet operation andefllcient control of the valve The lifter bracket 2 is provldedwith thepea-- sage 20 which communicates with the passage 18 of the connection19 and the groove 21 which extends peripherally around the lifterplunger 1 and communicates with the passages 22 which furthercommunicate with the chamber 16 of the lifter plunger 1, the groove 21and the pasages 22 thus enabling the chamber 16 to always remain incommunication with the passage 18 of the connection 19 in the closedposition of the/engine valve 4, as disclosed in Fig. 1, even when thelifter plunger 1 oscillates about its axis as it will tend to inoperation.

The chamber 18 is provided'with the threads 23, adjacent its open end,for, receiving the threaded end 24 of the adjusting screw 25 which isprovided with the shoulder portion 23 for engaging a wrench.

The adjusting screw 25 is provided with the extension portion 27,adjacent its shoulder portion 26, the extension portion 2! beingprovided with the chamber 28 which communicates with the passage sowhich further communicates with the chamber 16 of the lifter plunger 1.1

The inner end surface 29 of the chamber 2 forms a seat portion which iscontacted by the fiat surface of the hydraulic valve 31, the passage 30being thereby closed against. communication with the chamber 28 by thehydraulic valve 31 when maintained in contact with the surface 29 ashereinafter disclosed. The chamber 28 has an open end which is partiallyclosed by the flange 32 of the member 33, the flange 32 being pressed orotherwise suitably secured in the open end of the chamber 28, so as topositioncthe inner end of the member 33 at a point adjacent thehydraulic valve 31, to permit the hydraulic valve 31 to raise from itsseat contact on the surface 29 and allow the oil to be forced to flowunder and around the hydraulic valve 31 into the chamber 28 as soon asthevalve a closes. I I

The hydraulic valve 31 will be preferably constructed of a fiat-disc 'ofmetal of sumcient size as to fit loosely in the chamber 28, the sidewall surface of the chamber 28 and theinner end of the member 33 thusacting to maintain the hydraulic valve 31 in its proper position foropening and closing the passage 30.

' when the cam 34, of the camshaft 35, is in its closing position,relative to the engine valve 4, as disclosed in Fig. 1, the tappetclearance space 36 between the end surface of the extension portion 27and the end surface of the chamber 37 of .the piston or cap member 38 isin communication with the chamber 28 by means of the passages or spaces40 which are formed between the flatted sides 39 of the flange 32 of themember 33 and the inner side walls of the chamber 28 of the adjustingscrew 25.. The piston 38 is movably mounted'on and extends over the endof the extension portion 27 of the adjusting screwllb enclosing thetappet clearance space 36, as disclosed in Fig. 1, and the piston 38 maybe provided with the spherical surfacedl for contacting the end of thevalve stem 5. when the engine and its valve lifter mechanism is operatedat a very high rate of engine revolutions per minute, thc resilientmember or spring 42 may be interposed between the hydraulic valve- 31and the inner or under surface of the flange 32 to prevent the hydraulicvalve 31 from being opened by inertia forces developed by ahigh rate ofreciprocatim speed of the valve lifting mechanism.

It is also to be. noted that when the resilient member or spring 42,which may be of very light from the lubrication system of the enginethrough fills the tappet clearance 36 forcing the piston 41 weight and,tension, is used to counteract inertia forces acting on the hydraulicvalve 31, no obv Jectionable resultant thrust loads or reactions aretransmitted or added to the load of the valve spring 12 thus permittingthe use of lighter weight valve springs than is the case whererelatively heavy resilient members are used to control the operation ofhydraulic valves in valve lift mechanisms.

Fig. 2, discloses the cam shaft 35, which may be suitably mounted, ashaving revolved to a point where the cam 34 is in an opening positionrelative to theengine valve 12, theoil which filled the tappet clearancespace 36 having been displaced by the thrust of the valve liftermechanism. the taking up of the clearance space 36 between the extensionportion 2'7, of the adjusting screw 25, and the piston 38, tending toforce some of the oil, in the tappet clearance space 36 out into theatmosphere in the valve chamber-or box enclosing the valve liftermechanism, the oil being forced out between the outer surfaces of theextension portion 27 and the wall surfaces of the chamber 37 of thepiston 38, the very slight amount of oil thus being forced out in theform of a light and almost invisible spray around the upper side of theshoulder portion 25 of the adjusting screw 25, as inclicatedby thearrows, at 44, in Fig. 2.

It is tobe noted that the groove 21 of the lifter plunger 1 is inalignment with the passage 20 of the lifter bracket 2 only when thelifter plunger 1 is in a position corresponding to the closed positionof the engine valve 4 as disclosed in Fig. i in which position the oilis forced under pressure the conduit 17, the passage 18 of theconnection 19, the passage 20 of the lifter bracket 2, and into thegroove 21 of the lifter plunger 1 from where it passes through thepassages 22 into the chamber 16 of the lifter plunger 1. From thechamber 16, the oil under pressure passes through the passage 30 andlifts the hydraulic valve 31 from its .seat and into contact with theend of the member 33, which limits the opening movement of the hydraulicvalve 31, the oil passing under and around the hydraulic valve 31 andinto the chamber 28 of the adjusting screw 25, the oil further passingthrough the passages 40 and into the tappet clearance space 38. The oilunder pressure to raise and keep in contact with the lower end of thevalve stem 5 andforms an-oil film between the flange 32 and the end wallsurface of the chamber 37, the tappetclearance space 36 being enclolscdand sealed against leakage by the piston 88 being slidsbly or movablymounted with a good fit over the end of the extension portion 27. thushydraulically taking up the tappet clearancespaceinthevalveliftingmcchanism. Assoonas the lifter plunger 1 is movedfrom its position in whichthcenginevalvc4is closed,asin1"ig. 1,to aposition in which the engine valve 4 is balm opencd.asinl"k.2,thechamberldanditsoonnecting passages and chambers 30, 28, 40 and 36 becomedisconnected from the pressure line. of omam extension portion 27, theslight clearance space through which the oil is thus forced on thepressure stroke of the valve lifting mechanism also allowing for theescape of any air which may get into the connected chambers and passagesof the valve lifting mechanism.

Thus it will be noted that my invention will provide a very efiicientand quietoperation of valve-lifter mechanism in which the hydraulicmedium is retained without leakage in the valve lifter mechanism whenthe engine valve is in its open position thus resulting in no loss ofoil pressure as registered on the oil pressure gauge connected with theengine and further only permits a very slight amount of oil to bedisplaced from the valve mechanism in the form of a light spray duringthe pressure stroke of the valve lifter mechanism.

The lock nut 52 is provided for locking the adjusting screw 25 in itsadjusted position.

It is also to be noted that the piston 38 maybe constructed of verylight-weight and bulk which will add substantially no inertia load to beabsorbed by the valve spring 12, in high speed operation of an engine.Where it is desired to adapt my valve lifter mechanism to an engineequipped with overhead valves the adjusting screw mechanism is removedto a position adjacent the valves in the head and the lifter plunger 1,in Fig. 4, is provided with the passage 45 connecting with the chamber28 which is formed in the extension portion 46 of, the lifter plunger 1,

the piston or cap member 47' slidably fitting over the end of theextension portion 46 in a manner similar to the piston 38 and theextension portion 27 of the adjusting nut 25 in Figaal and 2. The piston4'? may be provided with the extension portion 48 having the chamber 49for receiving the end of the push rod 50 which is operatively connectedwith the valve mechanism in the head of the engine.

The lifter plunger 1 is provided with the enlarged end 51 for engagingthe cam 34.

It is to be understood that whereas a single valve lifter mechanism onlyis disclosed in the drawing, any member of valve lifter mechanisms maybe connected with the oil pressure lubrication system of an engine andmay be used with either inlet or exhaust engine valves.

Also it is to be understood that my invention may be adapted for use inmechanism, other than automotive units, where emcient control or quietoperation of tappet clearance means is desired.

It is also to be noted that the oil or other hydraulic medium which istrapped or isolated in the valve lifter mechanism of my invention formsa closed reservoir of oil which forms an absorbing cushion which willeffectually dampen any tendency for noise between contacting surfaceswithout appreciable losses of the oil.

It is also to be understood that, when desired, the pistons 41 and 47may be suitably mounted so as to extend within instead of extending overthe outside of the portions 3'7.

I claim:

1. In a valve lifter mechanism, the combination of a litter memberprovided with a chamber having an open end adjacent the valve to belifted, a fixed member suitably secured in the chamber of said liftermember, said fixed member having a portion extending to a point adjacentthe other of the ends of said chamber, a valve suitably mounted to-openand close said other end of said chamber, said valve being contacted bysaid portion of said fixed member to limitthe opening movement of saidvalve, a piston member slidably mounted on the outside of said liftermember to form a clearance space between the end surfaces of said lifterand said fixed members and the inner surface of said piston member, saidpiston member engaging the valve to be lifted, and means providingcommunication between said clearance space and said chamber of saidlifter member.

2. In a valve lifter mechanism, the combination of a litter plungerprovided with a chamber, a fixed member suitably secured in saidchamber, said fixed member having a flange portion for partially closingone end of said chamber, said fixed member having an extension .portion,a

valve member movably mounted to open and close the other end of saidchamber, said valve member contacting the extension portion of saidfixed member at the end of its opening movement, a resilient membersurrounding the extension portion of said fixed member and opposing theopening movement of said valve member, and a pis-.

ton member slidably mounted on the outside of said lifter member, saidpiston member engaging the valve to'be lifted.

3. In a lifter mechanism for an engine valve, the combination of a valvelifter member provided with a chamber having openings at its ends, apiston member for closing one of the ends of said chamber, said pistonmember being mounted over the end of said valve lifter member andcontacting the engine valve, .said valve lifter member and said pistonmember forming a tappet clearance space therebetween, a valve membermounted in and adapted to close the other end of said chamber, means forsupplying hydraulic medium under pressure to said chamber during aportion only of the lifting movement of said valve lifter member, amember-fixedly mounted in said chamber and provided with a flangepartially closing one of the ends of said chamber together with'anextension portion extending from said fiange to contact said valvemember in said chamber to limit its lifting movement,

and resilient means for facilitating the closing of said valve member insaid chamber, said resilient means being mounted around the extension ofsaid valve member in said chamber.

4. In a valve lifter mechanism, the combination of a member providedwith a chamber, means for supplying hydraulic medium under pressure tosaid chamber, a valve member suitably mounted in said chamber andcontrolling the flow of the hydraulic medium thereinto, said valvemember loosely fitting within said chamber to permit said valve memberto be guided in its movement by the walls of said chamber, a fixedmember provided with a flange for partially closing one end of thechamber of said first mentioned member, said fixed member being providedwith an extension portion for contacting said valve member to limit itsopening move- THEODORE M. MUELLER.

